Lysosomal Destabilizing Drug Siramesine and the Dual Tyrosine Kinase Inhibitor Lapatinib Induce a Synergistic Ferroptosis through Reduced Heme Oxygenase-1 (HO-1) Levels

Figure 4

Treatment of A549 and U87 cells with the combination of siramesine and lapatinib increases the intracellular labile iron pool (LIP). (a) Prussian blue staining for intracellular iron was performed and evaluated by light microscopy after 12 hours of incubation with DMSO, lapatinib (L), siramesine (S), or with the combination of lapatinib+siramesine (L+S). Representative images from 3 separate experiments. (b) Quantitative image analysis of Prussian blue staining. Standard error represents three independent experiments (). represents statistical significance of . (c) Calcein fluorescence assays. A549 and U87 cells were stained with calcein-AM (1 μM) after 12 hours of incubation with DMSO, lapatinib (L), siramesine (S), or with the combination of lapatinib+siramesine (L+S). Fluorescence signals were measured by flow cytometry. Standard error represents three independent experiments (). represents statistical significance of .

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